Sectional cartridge



Oct. 6, 1953 .1. w. ROSKE SECTIONAL CARTRIDGE Filed Dec. 26, 1950 0 6 40 M 3 l 2 e M 4 .M 23 W F Q. a w 6 a 2 0 6 W 3 2 m w M \\\\\\N\\\\\ M. aF 2 a A. n n4 m F INVENTOR.

Patented Oct. 6, 1953 UNITED STATES PATENT OFFICE SECTIONAL CARTRIDGEJack W. Roske, Crescent City, Calif.

Application December 26, 1950, Serial No. 202,692

2 Claims. 1

This invention relates to new and useful improvements in cartridges andthe primary object of the present invention is to provide a sectionalcartridge including a base cup, a shell and a novel and improved meansfor permanently securing the shell and cup together.

Another important object of the present invention is to provide asectional cartridge including a plastic shell that will be converted togas during the firing phase to assist in propelling the projectile andthereby permit reduction in the use of the propelling powder charge.

A further object of the present invention is to provide a sectionalcartridge including a colored plastic shell that will indicate the typeof projectile, thus eliminating the need for painting the tip oftheprojectile.

A still further aim of the present invention is to provide a sectionalcartridge that is extremely lighter in weight than all brass cartridgesand which will permit reduction in the use of critical materials such asbrass, copper and zinc.

Other objects and advantages reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming part hereof, wherein likenumerals refer to like parts throughout, and in which:

Figure 1 is an elevational view of the present cartridge;

Figure 2 is a vertical sectional view of the present cartridge andshowing the shell partially inserted in the cup; and,

Figure 3 is a vertical sectional view of the shell interlocked with thecup.

Referring now to the drawings in detail, wherein for the purpose ofillustration, there is disclosed a preferred embodiment of the presentinvention, the numeral represents the completed cartridge composed of ahollow plastic shell l2 and a base or cup [4 that is fabricated ofmetal, such as cartridge brass, an aluminum alloy, iron, steel, or othersuitable metal.

The cup I I is formed with an inwardly tapering smoothly curved recessHi, the inner wall of which is formed with a conical depression I8. Aconical lug or cam is integrally formed with the cup 14 and is disposedaxially within the depression I8. The lug 20 is formed with an axialbore 22 that communicates with a primer pocket 24 in the undersurface ofthe cup [4.

The shell l2 includes an inwardly tapered and smoothly curved lower orinner end 26 that is integrally formed with a cylindrical skirt or lipportion 28. A peripheral shoulder 30 is provided 2 about the shell l2 atits juncture with the end 25. The end 26 is formed with an axial bore orvent 32 that will register with the bore 22 when the shell is secured tothe cup.

As the shell I2 is forced into the cup, the end 26- will contact thewall of the recess l6 and the cam 20 will spread the skirt 2B and forcethe outer surface of the skirt against the wall of the depression Hi tofrictionally lock the shell and cup together. Any suitable cement may beinserted into the depression I8 to cause the skirt 28 to adhere to thewall of the depression I8.

Since the shell is constructed of plastic, the skirt 28 may be heated toa predetermined temperature before the end 26 is inserted into therecess l6 permitting flaring of the skirt outwardly by the cam 20 andthe skirt to adhere to the wall of the depression [8.

The shoulder 30 will abut one end of the cupto properly seal the end 26in the recess I6 and the body or shell I2 is constructed of coloredplastic to indicate the type cartridge and thereby eliminates thenecessity of coloring or painting the projectile tip 34.

The cartridge is intended primarily for use in aircraft machine guns andcannons where a reduction in weight of the individual cartridge is ofgreat importance, allowing a greater number of rounds to be carried.

It should be noted that the metal base acts as a gas seal to the rear,preventing damage to the gun and injury to the firer. A suitable cementmay be placed in the curved portion I6 01 the base to form a solid andwatertight band between the base and shell. This may be preferable toplacing cement in the depression l8 with the possibility of gettingcement in the vent, which could cause a misfire.

In view of the foregoing description taken in conjunction with theaccompanying drawings, it is believed that a. clear understanding of thedevice will be quite apparent to those skilled in this art. A moredetailed description is accordingly deemed unnecessary.

It is to be understood, however, that even though there is herein shownand described a preferred embodiment of the invention, the same issusceptible to certain changes fully comprehended by the spirit of theinvention as herein described and the scope of the appended claims.

Having described the invention, what is claimed as new is:

1. A sectional cartridge comprising a plastic shell having a. smoothlycurved and tapered inner end, a metallic cup having a smoothly curvedand tapered recess receiving the inner end of said shell, a peripheralshoulder on the shell abutting the cup, the inner wall of said recesshaving a conical depression therein, an upwardly extending conical lugforming the inner wall of said depression, and a skirt at the inner endof said shell for engaging said lug to be wedgingly fitted in saiddepression to secure the cup to the shell asftlie innernendsof thelshellisinserteduin the recess, said skirt; being provided with:an.axial borehaving 'a tapered upper end whose walls engage the upper end of saidconical lug as the skirt is fitted in said depression.

2. A sectional cartridge comprising ;a rplastic' portion of the shell,the lower wall of said recess having a continuous groove therein, saidgroove 1 having rlatera'lly and :uniformly spaced innerand routervwallsinclined relative to" the longitudinal axisof the cap and extendingdownwardly and outwardly from the recess, said skirt riding against theinner wall of said groove and against the outer wall of said groove tolock the shell and

